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Saturday, 4 July 2015

World of Tanks History Section: IS-2, the Guardsmen's Heavy Hammer

The success of the Red Army in 1944 was in no small part aided by the arrival of IS-2 (IS-122) heavy tanks on the battlefield. They were formed into independent heavy tank regiments. Considering the importance of the tasks they would complete, these units were assigned the title of Guards in advance. In any offensive, a regiment of IS-2 tanks was the ace up the sleeve of a tank corps commander, primarily as a reserve for fighting enemy tanks.

Each regiment consisted of four companies of five vehicles each, plus a commander's tank. Later, even larger units were formed, heavy tank brigades.

Battle elephants of the tank forces
During offensives, IS tanks protected the flanks or fought enemy counterattacks. They moved behind the front lines either in columns or small groups. They were also used to capture strongholds and transportation hubs. In this case, a tank brigade would have a platoon or company of IS tanks supporting its first echelon. This was an unpleasant and deadly surprise for German tanks that attempted to counterattack the T-34s or shoot at them from an ambush.

In defense, IS-2 tanks deflected German armoured attacks, destroyed MG nests and artillery. Tanks moved out in the direction of a likely attack and formed a checkerboard pattern, 1.5-2 kilometers in width and up to 3 kilometers in depth. There was also a practice of keeping some IS tanks on the front lines with the T-34s. In this case, the majority of the force was held back about five kilometers to cover all possible paths of enemy attack.

Good reconnaissance was always necessary to guarantee victory of a heavy tank unit. They had to know not only about the enemy, but the terrain. T-34s could cross swamps, sands, light bridges. The 46-ton IS could get stuck or cause unnecessary wear to their suspension. If a path had to be made, a sapper platoon could not be enough. This would have threatened the success of the mission.

Before battle, the tankers prepared carefully. All officers received maps with the current situation marked on them. Crews, down to the last crewman, were familiarized with the terrain and first line of enemy defenses. Everyone knew the role of their regiment in the breakthrough.

The IS-2 was a reliable tank and could travel up to 100 kilometers per day in skilled hands, exceeding the factory warranty period in engine-hours.

Anatomy of a tank elite
Even before the Great Patriotic War, Marshall Semyon Mikhailovich Budyonny said "The Red Army is strong, but our communications will be the end of us". As much communications equipment as possible was dedicated to the heavy tanks. Each IS-2 regiment HQ had several radios, both for contact with their vehicles and their superiors. Radios were on 24 hours a day, tank radios were on for at least several minutes during every hour. The HQ and regimental commander could always talk to the company commander and any individual tank. During extended stops, a telephone line was set up between the regiment and tank corps. The HQ had communications officers from every tank company. Aside from radios, the regiment also had armoured cars and motorcycles for couriers. Unlike the rest of the tank forces, communications in heavy tank regiments worked flawlessly.

How did IS tanks go into battle? Recce in force consisted of a tank platoon, sapper platoon in an APC, and a few squads of submachinegunners (20 men). This force went out 5-7 km ahead of the main units which were organized in a similar way, but without sappers.

In order to avoid ambushes, the commander of the regiment did not lead the charge, but rode in the third tank. The main column had an operations group: a fast Willys all-terrain vehicle, an APC with the HQ radio, an armoured car, and a few motorcycles for couriers.

After the tanks came trucks with ammunition, fuel, and supplies, medical and repair vehicles, a field kitchen. When they ran into the enemy, the tanks took up a battle formation, the operations group took its place behind the main forces, and the support vehicles retreated to cover.

When necessary, the infantry sent out couriers, guides, and guarded the tanks at night.

Guardsmen's Hammer in action
After the scouts discovered the location of the enemy, IS-2 tanks engaged from 1200-1500 meters, a range from which their guns were superior to the Germans', according to tank crews. The 122 mm gun was considered the best method of fighting enemy tanks at long range. Post-war authors heckle the IS-2 for having a small ammunition load, but it was usually sufficient for a day of fighting. The thing that the tankers did not like about the gun was the cloud of smoke emitted by every shot that revealed their location.

While early sights lacked field of view, combat in early 1944 showed that the tank could knock out a Panther at 1300 meters from any angle, and earlier tanks at a range of up to two kilometers. In July of 1944, the tanks received a new sight which, as was written in battle reports, demonstrated "tactical superiority of our sights over similar German sights".

The 88 mm German shell could penetrate an early IS-2 from 800-1000 meters. If the Soviet tankers were careless, they could be taken out from the flank, but if they followed the field manual and moved in "hops" after the T-34s, supported each other, and scouted the enemy carefully, then they were very tough targets.

A skilled crew could destroy even the most dangerous enemy vehicle. For instance, in battles for the Sandomierz foothold, on August 13th, 1944, in only one day, tanks of Lieutenants Klimenkov, Udalov, and Belyakov destroyed six King Tigers with no losses of their own.

On July 20th, 1944, near the city of Magerov, Lieutenant Boris Slyunayev, under cover from another tank, stealthily approached a crossroads and observed an enemy ambush for 10-15 minutes. After all enemies were accounted for, he fired several shots from a kilometer away, destroying a Ferdinand, an APC, and two guns with crews. In August of 1944, the same Slyunayev, covering the crossing of the Vistula, deflected 12 attacks, destroyed a Tiger, an SPG, and killed 50 Germans. In August, Slyunayev's regiment claimed the destruction of a 128 mm SPG, likely another Ferdinand. In 1945, Slyunayev destroyed an armoured train near the city of Lubenau.

According to memoirs of Soviet tankers, heavy German tanks strived to avoid sections of the front defended by IS tanks.

In March of 1945, IS tanks of the 82nd regiment spent about 3 ammunition loads per day, destroyed 13 tanks and SPGs, 42 guns, captured 5 SPGs and 40 locomotives. In Berlin, where IS-2 tanks were used in street fighting, the consumption of ammunition often reached 2-3 loads per day.

After the war, tankers wrote with full confidence: "There are difficult tasks, but there are no impossible ones. Our motto is "detect, strike, destroy". No one gets away."

7 comments:

The 88 mm German shell could penetrate an early IS-2 from 800-1000 meters.

Begging the question of "which 88 mm?" You'd think that by "first principles"-type reasoning that this armor resistance would refer to the 88/L56 carried on the Tiger I, but this bit of data is cited from the report of the 71st Independent Guards Heavy Tank regiment, after their fight with Tiger IIs sporting 88/L71s at Sandomierz Poland.

Very earlie IS 2 tanks had an armour of worse quality. http://www.battlefield.ru/js1-js2/stranitsa-7.html. The tank number 40255 was hit to the lower plate from 1000- 1100 m. Judging by the fact the driver was just injured the shell didnt penetrate but caused the spalling. But there is hard to just simple claim that earlie IS 2 can be frontaly penetrated from the such and such distance because its front absolutely has not the same effectivness. While the mantled and the lower plate can be penetrated by Pak 43 from more than 2000 m, the edges and top of the turret mask and the edges of the hull front should beounce its shell even from the short distance.

During offensives, IS tanks protected the flanks or fought enemy counterattacks. They moved behind the front lines either in columns or small groups....In this case, a tank brigade would have a platoon or company of IS tanks supporting its first echelon. This was an unpleasant and deadly surprise for German tanks that attempted to counterattack the T-34s or shoot at them from an ambush.

The "overwatch" role of IS-2s contrasts described above sharply with Tiger I panzerkeil tactics, where the heavies formed the "tip" of the attacking armored "spear", the rear of which was formed by the more vulnerable tanks.

I think the Soviet method much superior simply because it's not practical to build a reasonably mobile tank that is invincible to repeated hammering to even supposedly inadequate AT rounds, plus the tanks at the "point" of the spear are likely to get hit by AT flanking fire if their flanking support fails to maintain the advance or can be taken out by defending infantry.

The best example of the failure of German panzerkeil tactics is the failure of the Ferdinands at Kursk. The Ferdinand can be rightfully criticized for a number of shortcomings (choice of gun, speed and operational mobility, cost, etc) but the oft-cited lack of a machine gun was really only a shortcoming because of Model's misuse of his Ferdinands as the tip of his panzerkeil "spears", engaging Soviet infantry and tanks at short-range (despite the 88/L71's being not an optimal weapon against soft targets). If Model had used his Ferdinands the way as the Soviets used their IS-2s, in an overwatching role to provide supporting fire, their lack of a machinegun would have been relatively unimportant.

According to "WW II Ballistics: Armor and Gunnery" by Lorrin Rexford Bird and Robert D.Livingston, the 88 L/71 pierces 232mm of armour with the APCBC shell at 100m. The penetration method is 50% pen 50% of the time.

It also penetrates 153mm of armour at 3000+ meters, enough to destroy any IS-2 variant if it hits the turret or lower plate, and it penetrates the hull of the early IS-2 at 3000m+ as well. Assuming the UFP on the IS-2 mod. 1944 does not shatter or spall, resulting in a dead crew or disabled tank, the L/71 can penetrate the UFP from 1000m with APCBC and 2000m with APCR.

The L/71 has higher muzzle velocity by 150m/s with APCBC, making it's effective accuracy much higher in combat due to the fact that higher muzzle velocity weapons are easier to aim. It also has a much faster reload than the IS-2, reloading in 8s minimum compared to the IS-2's 15 seconds. All of this in addition to the fact that the Soviet 100mm and 122mm could not penetrate the Tiger II frontally anywhere but the non-mantlet areas of the turret and from <1500m means the Tiger II is wholly superior in tank to tank combat.

Overall:Tiger II can destroy IS-2 with ease from 3000m+ anywhere. IS-2 1944 can be taken out from 3000m+ in the lower plate and turret. In the case of UFP hit, from 1000m it will be destroyed, or 2000m with APCR. IS-2 BR-471 shell penetrates 175mm of armor at 100m, which is insufficient to knock out the Tiger II, even in the turret. However, 1945 BR-471B shell penetrates 201mm of armor at 100m, but only 172mm of armor at 750m. The IS-2 needs to be within 750m of the tiger II AND hit only the small non-mantlet areas of the turret to ensure penetration with the rarer BR-471B ammunition. IS-2 is effectively out ranged by a little more than 4 times.

Tiger II has a much faster reload, giving it an immense advantage in any kind of engagement. IS-2 minimum reload rate is 15 seconds, Tiger II minimum reload rate is 6 seconds. IS-2 is outmatched by nearly 3 times in fire rate.

Tiger II has a higher muzzle velocity, resulting in higher effective accuracy and much higher accuracy in deflection shots. Tiger II has 20% more muzzle velocity with APCBC than IS-2 APCBC. Mechanical accuracy is similar.

The D-10 (best Soviet AT gun) was only deployed on the SU-100. It needs to hit the small non-mantlet areas of the Tiger II within 1250m to destroy it, while the Tiger II can destroy the SU-100 from 3000+ meters anywhere on the front. The late war BR-471B ammunition penetrated 172mm of armor at 1250m. D-10 cannon muzzle velocity is also lower than L/71, and rate of fire as well.

The Tiger II UFP is effective 280+mm, meaning none of these cannons can penetrate it, so there is no point discussing it. Tiger II LFP can be pierced at similar ranges as the turret, but with correct angling of 10-20 degrees this weakspot is no longer penetrable.

Assuming equal combat scenario the Tiger II is far superior than any Soviet AFV in tank to tank combat. Myths of Soviet tank superiority are once again shut down.

In theory, yes. In practice, not so much.http://tankarchives.blogspot.ca/2014/12/is-3-reloads.htmlhttp://tankarchives.blogspot.ca/2013/03/is-2-vs-german-big-cats.htmlhttp://tankarchives.blogspot.ca/2013/10/is-penetration-tests.html